IMPROVEMENTS IN CAVITY CLOSURES

Abstract: A cavity closure for an opening in a building wall at which a window or door is to be inserted, comprising two U-shaped plastics extrusions (10, 10A) which can be interengaged together by means of fittings (12, 14, 16) to form a rectangular box-section member optionally of differing longer dimensions, so as to provide for the closure of cavities of three differing cavity widths according to the way in which the two elements are interengaged and the orientation in which the box-section is located in the cavity.

Description: Improvements in Cavity Closures This invention relates to a cavity closure. As used herein, the term "cavity closure" is intended to refer to a closure for the wall cavity at the periphery of an opening formed in the wall of a building to receive a window or door. The cavity closure subject of this invention may also be a former around which brickwork and/or blockwork is erected to form the window or door opening. Moreover, the cavity closure subject of this invention may also be but is not necessarily an acceptor arrangement which serves when located in the wall as a cavity closure to receive and locate one or more devices, for example a window or door receiving fitting, in the closed-cavity opening. According to one aspect of the invention, there is provided a cavity closure which, for any one or more sides of the opening formed or to be formed around the closure, comprises at least two closure elements which can be interengaged to form a closure having a portion which will extend into the cavity from the side of the opening with a spacing suited to the spacing between the cavity-defining walls, the closure elements being so formed that they can be interengaged in any one of a plurality of relative positions such that the portions which will project into the cavity are spaced to suit any one of a plurality of different cavity-defining wall spacings. Thus, currently buildings are erected with 50 mm, 65 mm or 75 mm cavity-defining wall spacings, as necessary to achieve satisfactory thermal insulation. A smaller spacing as aforesaid can be adopted if the internal wall is erected with blocks which inherently have good insulative properties. A described embodiment of the invention provides a closure which, with the same two closure elements, can be assembled to suit cavity-defining wall spacings of 50 to 64 mm, 65 to 74 mm and 75 to 89 mm. However, by addition of extension elements, a cavity-defining wall spacing of 90 to 105 mm can be catered for, if this is necessary in view of demands for higher U-values. In a preferred embodiment of the invention, two elements push-fit or snap-fit together to form a member of rectangular box section. This member may be located in the cavity with either its shorter first dimension or its longer second dimension extending across the width of the cavity, thereby to suit cavity widths of 50 to 64 mm or cavity widths of 65 to 74 mm. Moreover, the two elements alternatively push-fit or snap-fit together in a relation¬ ship which increases the first dimension to a third dimension greater than the unchanged second dimension, whereby the resulting box-section member will locate in a cavity of width 75 to 89 mm. Yet again, it is preferably also possible to push-fit or snap-fit the two members together with intervening extension strips to form a still more elongate box-section member which will suit a cavity width of 90 to 105 mm. Alternatively, instead of using extension strips, two differently dimensioned closure elements may be assembled to suit a cavity width of 90 to 105 mm. In all arrangements, the box-section presents at the end of the cavity at which the window or door opening is formed (built or more usually to be built around the closure), fittings which enable a reveal leg and/or a plaster trim and/or a connecting piece for a window frame to be push-fitted or snap-fitted to the box-section closure, and preferably also a fitting, on a side of the box member within the cavity, to which a fixing lug to be embedded in the wall, may be attached. The latter fittings preferably enable two fixing lugs to be fitted, respectively to be embedded in the inner and outer leaves of the wall. According to another aspect of the invention, therefore, there is provided a cavity closure which, for each of a plurality of sides of the opening formed or to be formed around the closure, comprises a box-section member the cross-section of which has a greater dimension in a first dimension than in a second dimension, the member being formed with exterior function-performing fittings arranged so that, when the extrusion is in use as a cavity closure with either its lesser or its greater dimension extending across the wall-defining cavity dependently on the width of the cavity, the same fitting functions are offered for use at the side of the box- section exposed to the opening. Again, 50 to 64 mm and 65 to 74 mm cavity widths can be catered for with one box-section member, whilst a box- section member of larger size can cater for 75 to 89 mm and 90 to 105 mm cavity widths. As above mentioned, particular fittings preferably to be available, in whichever orientation the box-section extends across the cavity, are a fitting for a reveal leg and a fitting for a plaster trim and/or window accepting element. The reveal leg fitting preferably comprises an undercut slot at each corner of the box-section, while the trim and/or acceptor element preferably comprises a receptor having a hook portion on each wall of the box- section. A preferred box-section is formed of UPVC by an extrusion process. In accordance with the first aspect of the invention it is preferred to extrude two elements of Li- section, or more preferably U-section, which have fittings enabling them to be push-fitted or snap-fitted together to form the complete box-section. Thus, the two basic elements which push-fit or snap-fit together to form the box-section member are preferably generally of a U-section, which fix together either with the legs overlapping, thereby to form the smaller box- section member, or with the legs end to end, thereby to form the larger box-section member. Extension strips acting as spacers between the free ends of the limbs of the two basic members can enable the more elongate larger box-section member to be assembled. The two basic elements generally of U-section preferably comprise identical extrusions. The interior of the box-section member which forms the cavity closure may be filled with heat insulating material . In one mode of use, the box-section, preferably itself assembled from two U-section UPVC extrusions and inside thermal insulation, for example foamed polystyrene or polyisocyanate extrusion, is cut to length and three such lengths are secured together to define the bottom and vertical sides of the periphery of the window or door opening. Additionally, a member such as steel angle is secured across the top where a lintel is to be provided. The steel member at the top may be temporarily supported to keep the cavity closure upright, which closure iε also to serve as a former for the brickwork and/or blockwork to be built around it to define the window or door opening. Preferably, where the members (box-section and steel) are connected to produce the former, the previously mentioned undercut slots (for receiving a reveal leg) at the corners of the box-section serve as ports for receiving the screws which hold the former together. Jigged holes may be provided in the wall of the box-section (and in the steel member) for this purpose. In this mode of use, generally for standard size window and door openings, the former may be made in the factory, but assembly on site is also possible. It is an advantage of the use of box-section for the former that it results in a rigid former which, except possibly for very large openings, does not require any bracing. In another mode of use, lengths of box-section and any other accessory fittings required are supplied in kit form to the building site, where a frame is assembled with the aid of angle brackets at the corners. After the brickwork and/or blockwork has been erected to form the window or door opening around the former, the angle brackets are removed. It will be appreciated that the above-described closure, when in position in an erected wall, forms a surround which closes the wall cavity on at least the bottom and sides of the opening in the wall. In accordance with a further feature of the present invention, it is therefore able to serve as an acceptor arrangement to receive fittings to be located in the opening, for example a fitting to receive a window or door frame. The invention proposes use of an intermediate element to secure the window or door frame in the surround. In practice, this element may serve for a different purpose instead of or additional to that of securing a window or door frame in position, and to this extent the closure of the invention is of wider applicability as an acceptor arrangement. According to this aspect of the invention, there is provided an acceptor arrangement which comprises an at least partial surround fixed in a window or door opening to serve as a cavity closure as previously described, said surround having a receptor, and an attachment element for securing to at least one side of the surround, said element having, in addition to at least one function- performing fitting, a receptor-cooperator which includes a deformable portion which is displaced during connection of the attachment element to the surround and restores or is restored to its natural position to fix the receptor- cooperator in engagement with the receptor. At least one function-performing fitting on the attachment element may be a plaster trim. Alternatively or additionally, at least one function-performing fitting on the attachment element may be a window-accepting fitting. Usually, and essentially in the case of a window-accepting element, attachment elements will be used at the two vertical sides of the surround. Plaster trim elements may be secured to two or three sides of the surround. At least in the case of a window accepting element, the attachment element will extend to the exterior side of the wall cavity, and provide the window-accepting fitting on the exterior side of the wall cavity. When the attachment element is formed with both a plaster trim and a window-accepting fitting, the plaster trim may be disposed between the receptor-cooperator and the window-accepting fitting, or vice versa. A preferred attachment element is a PVCU plastics extrusion of which the associated receptor-cooperator and one or more function-performing fittings form integral parts, extending along the length of said extrusion. in a preferred arrangement, the receptor in the surround is a slot overhung by a hook along one edge of the slot, while the receptor-cooperator on the attachment element is a hook which engages under the hook at the edge of the slot, together with a deformable wing, on the back of the attachment element hook, which restores or is restored, preferably the former, to engage the wall of the slot at the edge opposite to its hooked edge, thereby preventing retraction of the attachment element hook from its engaged position beneath the hooked edge of the slot. When the attachment element has a window-accepting fitting, said fitting preferably comprises a pair of spaced barbed tongues over which a recess formed on the window (or door) frame may be snap-fitted. Generally, the attachment element will be fitted to the frame first, and the frame with attachment element secured thereto then fitted in the surround. Such securing elements will be used at the two vertical sides of the frame, excluding the sill and the top, as previously mentioned. The cavity closure in accordance with the invention is now described by way of example with reference to the accompanying drawings, in which:- Figure 1 shows a basic PVCU extrusion; Figures 2 to 4 respectively show alternative manners of assembling two basic extrusions to form closures applied to wall cavities of differing widths; Figure 5 shows a PVCU extension piece; Figure 6 shows a modified cavity closure assembled with the aid of extension pieces; Figure 7 shows, in diagrammatic manner, a cavity closure frame constructed using closure members in accordance with the invention; Figures 8 and 8A show alternative ways of fitting a window frame in position in an opening where a 50 mm cavity closure is provided; Figures 9 and 9A show, in like manner to Figures 8 and 8A, alternative ways of fixing a frame in position in an opening where a 65 mm cavity closure is provided; Figure 10 shows a reveal leg; Figure 11 shows the assembly of two reveal legs to a cavity closure; Figure 12 illustrates fixing in position of the cavity closure in the cavity by use of a fixing lug; Figure 13 shows a plaster trim; Figure 14 shows the assembly of the plaster trim to the cavity closure; Figure 15 shows a combined plaster trim and window accepting element; Figure 16 shows the assembly of a window accepting element, without plaster trim, to the cavity closure; and Figures 17, 17A and 18 illustrate differing ways of fixing a PVCU window frame in position in a wall opening at which the wall cavity is closed by the cavity closure. Referring to Figure 1, there is shown a UPVC plastics extrusion 10 which is generally of U-section. The element is extruded with a number of shapings which constitute fittings for a variety of purposes. First the fittings 12, 14, 16 are referred to. By virtue of the fittings 12 and 16, two identical extrusions 10, 10A can be snap-fitted together in the manner shown in Figure 2. Alternatively, by use of the fittings 14 and 16, the two elements can be push-fitted or snap-fitted together in the manner shown in Figure 4. In the first case a box-section member 18 is formed; in the εecond case a box-section member 18A is formed. Figure 2 shows the cavity closure constituted by the box- section member 18 located in position to close a 50 mm wide wall cavity at a window opening. Figure 3 shows the same cavity closure 18 turned through a right angle to close a 65 mm wide wall cavity at a window opening. Figure 4 shows the cavity closure constituted by the box- section member 18A located in position to close a 75 mm wall cavity at the window opening. Referring to Figure 5, there is shown an extension piece 20. Figure 6 shows that two extension pieces 20 may be used to interconnect between two U-section extrusions 10, 10A at the fittings 14 and 16, thereby to form a more elongate larger box-section member 22. Figure 6 also shows that the box-section member 22 can be located in position to close a 90 mm wall cavity at a window opening. In practice, and especially when the closure is also used as an opening former around which the brickwork and/or blockwork is built, then as shown in Figure 7 three lengths of box-section cavity closure member 18A, 18B and 18C (or 22A, 22B and 22C) are fixed together by fixing screws 62 to form the bottom and two vertical sides of the cavity closure around which the window or door opening is to be formed. Additionally, a length of steel angle 64 constituting a tie bar is screwed in place, by means of screws 62A, across the top of the closure where a lintel is to be provided. For convenience and clarity, in Figure 7 the fittings formed in the box-section for plaster trim and/or window acceptor elements are omitted, and only the slot 36 for a fixing lug is indicated. Additionally, however, the slots 34 which can be used to fit one or more reveal legs are shown. Importantly, these are also used as ports for receiving the screws 62 and 62A, in particular as indicated by the dashed lines 66 which pass through jigged holes 68 formed in the wall of the box-section lengths and likewise punched holes 70 in the steel tie bar 64. Hole 72 in the steel tie bar 64 defines a means for fixing to temporary jambs to ensure exact upright positioning of the closure while it is built in. Figure 7 is especially applicable to the construction of a cavity closure to serve as a former on site, but for standard size windows, at least the three cavity closure members 18A, 18B and 18C (or 22A, 22B and 22C) may be factory assembled. Whether supplied to the site as unassembled lengths or as an assembled frame, a reveal leg will commonly be assembled to the frame in the factory, aε referred to later. In Figure 8, a timber window frame 24 is shown fixed in a set back poεition in the window opening, generally in line with the cavity closure 18. Fixing of the window frame is in this case effected at 26. In Figure 8A, the window frame 24A is set forward, and fixed in position at 28. The same manner of window frame fixing is possible for all dimensions of wall cavity width and cavity closure. Thus, Figures 9 and 9A show, in like manner, the fixing of the window frame 24 or 24A in a closure for a 65 mm wall cavity. Figures 8, 8A, 9 and 9A also show thermal insulation 30 filled within the box-section cavity closure 18, and a reveal leg 32, shown separately in Figure 10, which engages in a recessed slot 34 in one corner of the box- section closure. If required, as shown in Figure 11, two reveal legs 32, 32A may be fitted. In this respect it is important to note that two slots 34 are available at the two exposed corners of the box-section closure 18, 18A or 22, and in both orientations of the box-section closure 18. The fittings 36 on the basic U-section extrusions are also to be noted. Figure 11 shows a fixing lug 38 secured to the cavity closure 18 by use of one of the fittings 36. The same fixing lug 38 can be employed when the cavity closure 18 is in the orientation at right angles, as shown in Figure 12. Figure 13 shows a trim 40 for plaster work. This trim 40, in the manner exemplified in Figure 14, may be secured in any one of the fittings 42, 44 or 46 when on the exposed side of the box-section closure 18, 18A or 22. Figure 14 shows the fitting 44 in use. Thus, in more detail, the plaster trim element 40 is approached at an angle, right to left, towards the closure 18, on a line which inserts the hook 40B of the receptor- cooperator under the hook 44A of the receptor slot 44. As the hook 40B enters into position, the wing 40C of the receptor-cooperator is deformed, as indicated by the arrowε. Aε the hook 40B progreεεeε into poεition, the plaster trim element 40 is straightened in line relative to the cavity closure 18, eventually to inεert the hook 40B in full engagement beneath hook 44A, whereupon wing 40C iε displaced clear of the right hand side of the receptor slot 44 and is able to spring back into its natural position, in which it engages the wall 44B of the receptor slot 42 remote from its hooked edge. The plaster trim element 40 is then locked in position. Wing 40C is preferably resilient, but could be deformable, as by means of a line of weakened plastics material, in which case it can be pushed back into its normal position, after full engagement of the hooks, so as to engage the wall 44B of the receptor slot 42. It will also be appreciated that the plaster trim element 40 could instead be engaged into the receptor-cooperator 42 or, when the closure is used in the orientation shown in Figure 3, into the receptor-cooperator 46. The combined plaster trim/window acceptor element 48 of Figure 15 or element 48D of Figure 15B can be engaged into one of the receptor slots 42 or 44 or 46 in analogous manner to the manner of engagement of the plaster trim element of Figure 13. Figure 16 shows, in like manner to Figure 13, an attachment element 49 having only a window-acceptor fitting 50A, engaged into the cavity closure 18 at the slot 44 . The attachment element 48 shown in Figure 15A has the window-accepting fitting 50 located between the plaster stop 4RA and the receptor-cooperator 48B. However, as εhown in Figure 15B, it is equally posεible, and probably more usual in the case of a window frame to be set back on the exterior side of the wall cavity, for the plaster trim 48A to be positioned between the window-accepting fitting 50 and the receptor-cooperator 48B. This is also shown in Figure 17, wherein PVCU plastics window frame 52 is shown secured to the window-accepting fitting 50 of attachment element 48D, which also has a plaster stop 45A. The receptor-cooperator of the attach¬ ment element 48D is again engaged into the slot 44 of the cavity closure 18. For completeness, in Figure 17, there is also shown the fixing lugs 38 employed to fix the cavity closure in the wall cavity. The fixing lugs 38 are engaged into receptor slots 36 formed in the cavity closure. It will also be seen from Figure 17 that the interior of the cavity closure is filled with thermal insulation 30. It will, however, be clear from Figure 17A that the PVCU window frame 52 may instead be fixed in position by means of a fixing lug 54. To complete understanding of the cavity closure, Figure 18 shows the arrangement at the sill of a window. Similar reference numerals are employed to those of preceding figures, but the sill member 56 and its fixing 58 are shown, together with an interior reveal leg 32. Usually, however, an interior reveal leg is not required. Thus, when a window or door frame iε being inεtalled in accordance with Figures 17 and 18, attachment elements 48 (or 48D) will be εecured to the two vertical εides of the frame 52, the frame stood on the sill 56 and then pivotted into position to engage the attachment elementε 48 (or 48D) with the fittingε 44, making use of the inherent resilient deformability of the attachment elements. The above-described arrangements can also be used in relation to cavity closureε at door openingε, aε well aε window openings.

Claims: Cl a ims 1. A cavity cloεure which, for any one or more sides of the opening formed or to be formed around the closure, comprises at least two closure elements which can be interengaged to form a closure having a portion which will extend into the cavity from the side of the opening with a spacing suited to the spacing between the cavity-defining wallε, the cloεure elementε being εo formed that they can be interengaged in any one of a plurality of relative positions such that the portions which will project into the cavity are spaced to suit any one of a plurality of different cavity-defining wall spacings. 2. A cavity closure according to claim 1, wherein the two elements push-fit or snap-fit together to form a member of rectangular box-section. 3. A cavity closure according to claim 2, wherein each element is generally of U-section. 4. A cavity closure according to claim 3, wherein the two elements carry fittings enabling them to be interfitted as a rectangular box-section having the option of either one of two differing longer dimensions. 5. A cavity closure according to claim 4, in combination with extension elements which can be inter¬ posed between the two U-section elements to provide a rectangular box-section member of a third differing longer dimension. 6. A cavity cloεure according to any of claims 1 to 5, having fittings for the attachment of other elements thereto, the assembled elements providing a rectangular box-section which presents similar attachment fittings both along the side of itε εhorter di enεion and the εide of its longer dimension. 7. A cavity closure according to any of claims 1 to 6, wherein the two elements are extruded elements. 8. A cavity closure according to claim 7, wherein the elements are made of extruded PVC. 9. A cavity closure according to any of claims 1 to 8, having thermal insulation inserted within the box-section, 10. A cavity closure which, for each of a plurality of sides of the opening formed or to be formed around the closure, comprises a box-section member the cross-section of which has a greater dimension in a first dimension than in a second dimension, the member being formed with exterior function-performing fittings arranged so that, when the extrusion is in use as a cavity closure with either its lesser or its greater dimension extending across the wall-defining cavity dependently on the width of the cavity, the same fitting functions are offered for use at the side of the box-section exposed to the opening. 11. A cavity closure according to any of claims 1 to 10, in which the box section member carries attachment fittings for a reveal leg and for a plaster trim and/or window or door frame accepting element. 12. A cavity cloεure according to claim 11, wherein the reveal leg fitting comprises an undercut slot at each corner of the box-εection. 13. A cavity cloεure according to claim 11 or claim 12, wherein the fitting for a plaster trim and/or window accepting element compriseε one or more hook-εhaped projections on each εide of the box-εection. 14. A cavity cloεure according to any of claimε 11 to 13, in combination with one or more reveal legs. 15. A cavity closure according to any of claims 11 to 14, in combination with a plaster trim and/or window accepting element. 16. A cavity closure surround for a window or door opening in a building wall, comprising three or four lengths of box-section comprising a cavity closure according to any of claims 1 to 15, cut to length and secured together to define at least the bottom and sides of the periphery of the opening. 17. A cavity closure surround according to claim 16, wherein the brickwork and/or blockwork forming the wall is erected around the closure, which thereby also constitutes a former for the window or door opening. 18. An acceptor arrangement which comprises an at least partial surround fixed in a window or door opening to serve as a cavity closure surround as claimed in claim 16 or claim 17, said surround having a receptor, and an attachment element for securing to at least one εide of the surround, said element having, in addition to at least one function-performing fitting, a receptor-cooperator which includeε a deformable portion which iε displaced during connection of the attachment element to the surround and reεtoreε or is restored to its natural position to fix the receptor-cooperator in engagement with the receptor. 19. An acceptor arrangement according to claim 18, wherein at least one fitting on the attachment element is a plaster trim. 20. An acceptor arrangement according to claim 18 or claim 19, wherein at leaεt one fitting on the attachment element is a window or door frame accepting fitting.

Inventors: WEBSTER BRIAN CHRISTOPHER, WEBSTER, BRIAN, CHRISTOPHER
Applicants: ANGLIAN WINDOWS LTD, WEBSTER BRIAN CHRISTOPHER, ANGLIAN WINDOWS LIMITED, WEBSTER, BRIAN, CHRISTOPHER
Application year: 1994
Main classification: E06B1
IPC codes: E06B1